species. There are numerous studies that have supported that Pyrobombus is paraphyletic and suggest the Pyrobombus belong in two different phyletic lines. In a study by Plowright and Stephen (1973) have examined 18 different enzymes and found the taxon sample had close relationships with B. jonellus and B. frigidus. Their studies have also aligned with other independent researchers."More extensive molecular analyses suggest Pyrobombus is monophyletic and most closely related to Bombus s.s. and Alpinobombus." (Williams, Paul. 2006)"A genus-wide phenetic study of wing venation by Plowright and Stephen (1973) resulted in a polyphyletic Pyrobombus, with some species more closely related to species of the subgenera Melanobombus." (Williams, Paul. 2006) Habitat and nesting Principally, Pyrobombus have their nests underground rather than the surface, which is common amongst the Bombus. In design, Pyrobombus constructs its nest with no elaborate entrances to its underground canal. Generally, plant material such as dry grass, sticks, petals, and other small deposits would be collected and accumulated around and or in the nest canal for camouflage. This camouflage of its nest is also known as a pseudo-nest particularly to avoid predators and protection against bad weather. These colonies would often be small with some species being flexible with their site preference. European Pyrobombus species have the tendency to be more stubborn in site preference, whereby their selection of nesting areas are limited. In the nest, there are cells. These cells are pollen lumps that are occupied by eggs and for the young. Pyrobombus have their eggs isolately laid each in a subcell laid vertically for the first cells in position which is the most common behavior amongst all bees except for the Alpinobombus. "The arrangement of eggs in the first cell arrangement for Pyrobombus is generally two eggs at the center and three on each side, forming three rows." Upon the population of Pyrobombus developing and growing, the nests would inevitably need to expand in size. The construction of new cells would lay on top of the previous cells. This act would be also known as brooding. The following broods would have eggs laid horizontally or on top in position. Pollination Pollination is important to preserve the ecosystem. It heavily relies on pollinators, like Pyrobombus. Pyrobombus collect pollen from a variety of flora by using its hind legs (scopa) and have pollen trapped between the body hairs. Through vibrating at high frequencies, pollen can be expelled from the